Cyclic adsorption processes for recovery of h2s from natural gas employing two activation cycles



Nov. 25, v1958 Filed OCC. 7, 1957 E. B. Ml CYCLIC ADSORPTION PROCE DF HS FROM NATURAL LLER 2,861,651

SSES FOR RECOVERY GAS EMPLOYING TWO ACTIVATION CYCLES 6 Sheets-Sheet l INVENTOR e Ewzfrjzm Nov. 25, 1958 E. B. MILLER CYCLIO ADSORPTION PROCESSES FOR RECOVERY OF Hzs FROM NATURAL GAS EMPLOYING TWO ACTIVATION CYCLES 6 Sheets-Shea?I 2 Filed Oct. '7, 1957 R. w .WM m WMI A N m E ,A m M 2 www MAA@ Nov. '25, Y1958 E. B. MILLER 2,861,651 cYcLrc ADsoRRTIoN RRocEssEs FoR RECOVERY 0E Hs FROM NATURAL GAS EMPLOYING v Two ACTIVATIONCYCLES F/iled oct. '7, 1957 F l G. 4.

6 Sheets-Sheet 5 INVENTOR EMR ATTORNEYS Nov. 25, 1958 E. B. MILLER 2,861,651

CYCLIO AOSORPTION PROCESSES FOR RECOVERY OF Hzs FROM NATURAL GAS EMPLOYING TWO ACTIVATION CYCLES Filed Oct. 7. 1957 e sheets-Sheet 4 J/ o F l G0 5| 0 o o o o o o o o o 0 O if o o o o Q J5 0 o o o o f o o o o o o o o o o 5 o o \o o o o o O o O FIG. 6.

I N VEN TOR BY MRW ATTORNEYS Nov. 25, 1958 E. B. MILLER cYcLc ADsoRPTIoN PROCESSES FOR RECOVERY OFH S FROM NATURAL GAS EMPLOYING TWO ACTIVATION CYCLE 6 Sheets-Sheet 5 Filed Oct. 7, 1957 R O T N E V 1N.

ATTORNEYS Nov. 25, 1958 E. B. MILLER v CYCLIC ADSORPTION PROCESSES FOR RECOVERY OF HZS FROM NATURAL GAS EMPLOYING TWO ACTIVATION CYCLES 6 Sheets-Sheet 6 Filed O01.. 7, 1957 FIG.

FIG. IO.

INVENTOR Ziws'z' i MLLEB ATTORNEYS CYCLIC ADsoRPrIoN PROCESSES FOR RECQY- ERY OF 112s FROM NATURAL GAS EMPLOYING rrwo ACTIVATION CYCLES Ernest B. Miller, Houston, Te'x., 'assignor to Jefferson Lake Sulphur Company, New Orleans, La., va corpora- 'tion-ol. N ewvJersey .Appiietionoaabem 1951, serialNo. tenses :4Claimst (ci. iss-114.2)

This invention relates to adsorption processes for treating fluids to remove and/or recoverparticular constituents of the fluid and has more particular reference to cyclic adsorption processes ofthe type comprising an adsorption cycle in which the fluid being treated passes through one or more adsorption stages of .the adsorber; and an activa- .tion cycle employing a captive `activationgas recycled through a'heater and the activation stage of the adsorber to desorb -the particular constituent accumulated in the adsorbent material `and reactivate the material.

One object of the present invention is to provide a novel and improved cyclic adsorption process for treating fluids to remove and/or recover a particular constituent therefrom, as characterized above, which employs a multi-stage activation cycle and a multi-stage purging cyle to effect an e'icient and substantially coiriplefteV removal of the particular constituent to be removed and/ or recovered 'from 'the fluid 'being treated.

A further and more limited object of theV present 1invention is to provide a novel and improved cyclic adsorption process, as characterized above, for removing and recovering HZS from natural gas.

Other objects and advantages of the invention will appear in the following specification when considered 'in connection withthe accompanying drawings, in which:

Fig. 1 is a schematic v'iew showing one embodiment 'of apparatus and arrangement thereof for carrying out the method of the present invention and the flow ofthe various fluids therethrough.

Fig. 2. is a side elevationallview of the adsorber shown in Fig. l; Y

Fig. 3 is a plan view of the apparatus shown in Fig. 2;

Fig. f4 is a vertical-sectional View taken on the 'line 1;4 -of`Fig.'3, but omitting the "driving apparatus;

Fig. 5 is a horizontal sectional view taken Aon the line 5 5 of Fig. 4;V n

Fig. 6 is a fragmentary sectional v view taken on the 4lined-6 -of Fig. 4, showing the manner of bracing the upper ends yof the elongated adsorbent material containing vessels;

Fig. 7 is a fragmentary sectional view taken on the line 7--7 of Fig. 4, showing the manner of supporting the lower'ends of the -elongatedadsorbent material-containing vessels;

Fig. 8 is a horizontal sectional view taken on the Yline ,8--8 of- Fig. 4;

Fig. 9 is a detailed sectional view, taken on the line 9--9 of Fig. 8;

Fig. l is afvertical vsectional View, with parts broken away, of the adsorbent material containing vessels shown in Fig. 4, showingthe containers for holding the adsorbent material mounted therein; and

Fig; 1l is a plan view of the container shown in Fig. l0.

The present invention provides a novel and improved process for removing and/or recovering particular constituents from fluids. The process isa continuous cyc'lic adsorption process employing an adsorber'in which at UnitedStates Patent O ICC Z least one `bred of adsorbent material is maintained ina plurality of stages and, in general, comprises an 'adsorption cycle in which a continuous flow :of the fluid :being treated is directed, under high pressure,Y through 'oneor more adsorption stages so that substantially vall of the, particular constituent content of the fluid, which is toghe removed, will be adsorbed by -the beds yof, adsorbent material in the adsorbent stages; a multi-stage activation cycle carried out in two steps, in each of Awhich a flow of a captive activation medium, under high pressure, is V,continuously recirculated through a heater and one activation stage of the adsorber to desorb the accumulated particular constituent from the adsorbent material therein, the two activation stagesbeing called vthe first activationstage and the second activation stage; and a bleedingstepjin which a determined quantity of the flow ofthe recycling activation medium used in the second activation stage is bled off into the recycling ow of the activation medium used in the first activation stage, whereby the recycling activation medium used in the first activation stage -will become highly concentrated in desorbed particular' yconstituent; a multi-stage purging cycle .carried out in three steps, a first purging step in which a portion ofthe I ecycling activation medium used in the first `activation stage is continuously diverted and passed into a stagey imvmediately preceding the first activation stage,` called ,the

irst purging stage, to pushy out all slippage fluid contained in the stage andthe adsorbent material therein, -withv the effluent fluid from the first purging stage passing intothe ilow of the fluid being treated on its way to the adsorber, a second purging step in which a portion ofthe recycling activation medium used in the second activation stage fis continuously diverted and passed into yas'tage interposed between the first and second activation stages called the second purging stage, to push out all slippage iluidcontained therein, with the effluent fluid from the second purging stage passing into the recycling flow of activation medium used in the first activation s tag'eand athird purging 'step in which a portion of the ow yofthe effluent stripped fluid being treated flowing from the last adsorption stage of the adsorber is continuously diverted and passed into a stage immediately following the second activation stage, called the third' purging stage, to ypush out all slippage fluid lcontained therein, with the eflluent fluid from the third purging stage passing into the recycling flow of activation medium used inlthesecond acti A1- tion stage; the periodical shifting ofthe relative positins of the particular adsorbent material andthe particular ow of uid through each stage, either by movingtlie beds successively through the stages or by shifting ythe ows of fluid through the several stages, so that each Stage becomes, in succession, a first purging stage, a rst'activation stage, a second purging stage, a second ractivation stage, a third purging stage, and an adsorption stage; and a particular constituent recovery cycle in which a portion of the recycling activation medium used'in the first'activation stage, after its concentration of desorbed particular constituent has built up to a predetermined concentration by volume, is continuously withdrawn, as'the finished product. A

While the novel and improved process ofthe invention may be employed to remove and/or recovervarious constituents from various uids, it is particularly adapted -f'or removing and recovering H28 from natural -gas andsuch a process will hereinafter be described. And, fwhile-any suitable usual type .of adsorption yapparatus may heemployed to practice the process of the 'present invention; for the purpose of illustration, the process Awill ,be `described as carried out -by employing a rotary .type 0f adsorber in which a plurality of elongated, .upright closed vessels containing adsorbent material are rotated directly in succession and substantially continuously through the various stages of the adsorber.

Referring now to the drawings, there is shown, in F ig. 1, one embodiment of apparatus and arrangement thereof for carrying out the process of the present invention. The apparatus shown includes a seven stage rotary adsorber 1, two stages of which are employed as adsorption stages, two stages of which are employed as activation stages, and three stages of which are employed as purging stages; two heaters 2 and 2 for heating the acti- -vtion gas'used in the two activation stages; and two fans -`or blowers 3 and 3 for circulating the activation gas Nthrough the activation stages. t

' -2 The natural gas, from which substantially all water vapor and condensable hydrocarbons have previously been -removed therefrom, is delivered, at high pressure, from -the usual compressor or source of supply (not shown) to the first adsorption stage of the adsorber by means of a fpipe line 4. The gas passes through the first adsorption stage, where some of the H2S content is adsorbed. From the first adsorption stage of the adsorber, the gas passes -through pipe line 5 to the second adsorption stage of the adsorber, where additional H2S is adsorbed. From the second adsorption stage of the adsorber the gas passes through pipe line 6 to its various points of use.

The captive activation gas for the first activation stage `lis heated in the heater 2 to a temperature of about 400 F. and, from ,the heater, passes through a pipe line 7 to the rst activation stage of the adsorber. The heated gas passes upwardly through the first activation stage, desorbing the accumulated H28 from the adsorbent material therein. The heated gas and the H2S desorbed from the adsorbent material pass through a pipe line 8 to the blower or fan 3 and are recirculated by the blower through a pipe line 9 and the heater 2 back through the vfirst activation stage of the adsorber. This recirculation process is continuous. This recirculating captive stream `of gas is allowed to become highly concentrated in desorbed H28 by passing directly from the activation stage outlet back to the heater without any intermediate cooling. After the concentration of H2S in the captive gas stream has built up to the desired degree, a portion thereof is continuously diverted through a pipe line 10 as the finished product.

The captive activation gas for the second activation stage is heated in the heater 2 to a temperature of about `400 F., and, from the heater, passes through a pipe line 11 to the second activation stage of the adsorber. The heated gas passes upwardly through the second activation stage, desorbing the accumulated H28 from the adsorbent material therein. The heated gas and the H2S desorbed from the adsorbent material pass through a pipe line 12 to the blower 3 and are recirculated by the blower through a pipe line 13 and the heater 2 back through the second activation stage of the desorber. This recirculation process is continuous.

The vessels which contain the adsorbent beds are rotated so that each vessel passes in succession through the various stage of the adsorber. As the vessels move through each stage they are filled with the particular gas flowing through the stage and carry this gas into the next or succeeding stage in their rotary movement. This carrying of gas from one stage to the other by the vessels is called slippage.

In order to prevent slippagegas from the first adsorption stage, which would consist of the raw gas being treated, from being carried over into the first activation stage and diluting the recycling activation gas, a purging 'stage is interposed between the first adsorption stage and lthe first activation stage, called the first purging stage.

In order to prevent slippage gas from being lcarried over from one activation stage into the following activa- Ation stage, a purging stage is interposed between the first and second activation stages called the second purging stage.

Also, in order to prevent the slippage gas from the second activation stage, which contains some H28, from being carried over into the last adsorption stage, where it would pass out of the adsorber with the outgoing stripped natural gas, a purging stage is interposed between the second activation stage and the last adsorption stage, called the third purging stage.

A portion of the captive activation gas employed in the first activation stage owing to the heater 2 through pipe line 9 is continuously diverted through pipe line 14 for use as the purging gas in the first purging stage. The efliuent gas from the first purging stage passes through pipe'iline 15 into pipe line 4 to' join the ow of the raw gas being treated on its wayto the first adsorption stage of the adsorber. This permits the purging gas in the first purging stage to push the slippage gas inthe first 'purging stage, which consists of raw natural gas, back into the incoming raw natural gas being treated on its way to the adsorber and, as the gas used as the purging YThe effluent gas from the second purging stage passes through pipe line 17 into pipe line 8 and joins the recycling activation gas used in the rst activation stage. This permits the purging gas in the second purging stage to push the slippage gas in the second purging stage, which consists of activation lgas from the first activation stage, back into the recycling stream of the activation gas used in the first activation stage. And, as the gas used as the purging gas in the second purging stage consists of diverted activation gas from the second activation stage, the slippage gas from the second purging stage into thesecond activation stage consists of activation gas so that the recycling activation gas in the second activation stage is not diluted.

A portion of the effluent stripped natural gas flowing from the second or last adsorption stage of the adsorber through pipe line 6, is continuously diverted through pipe line 18 for use as the purging gas in the third purging stage. The efuent gas from the third purging stage passes through pipe line 19 into pipe line 12 and joins the recycling activation gas used in the second activation cycle. This permits the purging gas in the third purging stage to push the slippage gas in the third purging stage, which consists of activation gas from the second activation stage, back into the recycling stream of the activation gas used in the second activation stage. And, as the gas used as the purging gas in the third purging stage consists of diverted efliuent stripped natural gas from the second adsorption stage, the slippage gas from the third purging stage into the second adsorption stage would onsist of stripped natural gas so that no H2S would ybe ost.

A valved pipe line 17 connecting pipe line 13 to blower 3 permits bleeding a regulated quantity of the recycling activation gas used in the second activation stage into the recycling stream of activation gas in the first activation stage.

The employment of the two activation stages, the three purging stages, and the regulated bleeding of the captive stream of activation gas from the second activation stage into the first activation stage, as above outlined, effects a very complete removal of H28 from the gas -being treated, and efiiciently effects the build up of the desired concentration of H28 in the hrst captive activation stream,

Vdistributive at which point .apporton ofthe recycling activation `gas isbled koft through the pipe line as theiinished product orsent to a condenser for liquefaction.

While any suitable type of rotary adsorber maybe employed to practice the method of the present invention,

"the adsorber illustrated is generally similar to the duid treating apparatus shown in my I'Patent No. 2,751,033, issued June '19, 1956, for 'Fluid Treating Apparatus.

.As shown in Figs..2 to l1, inclusive, the adsorber co/mprises an 'elongated upright vcylindricalpressure vessel 20 having flanged vverticallyaligned'circular openings 21, 22

'suitable cap kbearing carried by the upper closure member 23 and with "its jlower end 'extending through a suit- 'able shaft seal, secured'to the bottom of the lower closure 'member 24; a vertical 'shaft 27 coupledto'the bottom end .of the shaft 26 and connected to suitable differential gearing, indicated at 28, driven by a motor 29; a support disc 30 vtixedly mounted on the'shaft 26 for rotation therewith 'within said pressure vessel and providing support for a plurality of elongated uid treating material containing cylindrical vessels 31; upper and lower distributive assemblages, indicated'generally at 32, 33, each assemblage comprising anannular,stationary'member 34 having a plurality of compartments or manifolds formed therein,

a tube sheet discvalve 35 slidably mounted on the shaft -each connecting the upper end rportion of one of the vessels 31 and the tube sheetdisc valve 35fof the upperl distributive assemblage; a plurality of flexible pipes 39,

`each connecting the lowerend portion of one of the Vessels 31 and the tube-sheet disc valve 35 of the lower distributive assemblage, la plurality of inlet-outlet conduits, seven such being shown, 40, 41, 42, 43, 44, 45 and 46, connected 'to the annular Vstationary member 34 of the --upper distributive assemblage and extending upwardly through the upper capclosure member 23, for the ingress and egress of fluids to and from the upper stationary member 34; and a plurality of inlet-outletconduits, seven suchbeing shown, 40', 41', 42', 43', 44', 45 and 46', conne-cted to the annular stationary-member 34 of the lower assemblage and extending downwardly through the lower cap closure member 24`for the ingress and egress of fluids to and from the lower stationary member 34.

The cylindrical pressure vessel 20 and the cap cover `members 23,124 are preferably made of heavy boiler plate.

The flanges formed in the peripheries of the openings 21, 22 of the vessel20 and -the'peripheriesof ythe cap cover members 23, 24 are preferably formed of heavy iron rings, rectangular in cross section `and vare welded to the peripheral edges of the openings and the cover plates, as indicated at 47. n

Thexshafting 26, preferably andas shown, is 'formed of three Sections, an upper section 48, an intermediate section 49 and a 'lo-wer or bottom section 51). The upper and lower sections 4S and 50 consist of'solid rod, round in cross section. The intermediate section 49 consists yof a hollow pipe havingian internal diameter considerably larger than the diameters of the upper and lower sections.

The upper section 43 has its upper end journaled in a suitable lcap bearing 51 carried by the upper covermember 23 and itslower end supported ina support bushing 52 mounted in the upper end of the intermediate section 49, Witha pin 53 passing through the two sections and the Ybushing :for rigidly andvdetachably securing the two sections together.

in the form ofgshort sectionsloflstructuralangles.

The 'bottomsection '50 vrhas its upper end engaged in Ya support bushing 54 'm'ounted'in the lower end of the Pin- 'termediate section 49 with a pin 55 passing through the two sections andthe bushing for rigidly and detachably securing the .two sections together, and with its "lower end extending through 'the lower cover member 24 and Va suitable shaft seal 56 and coupled to the upper end of the shaft 27.

The support disc l30 which supports .the cylindrical vessels 31 is composed of two semi-annular 'flat pieces 5.7,

the inner adjacent vstraight edges of which areprovided with ftangeswhich are `bolted together 'to form 'the complete disc. This is to `permit of assembling the disc within the pressure vessel 20. n

The disc 30 "(s'ee Figs. 4 and Y7`) is viiXedly secured, .as by betting, to a collar S8 fixedly secured 'to the intermediate section 49 of J.the .shaft 2.6, so Ythat the 4disc'will rotate with the shaft. The outer peripheral edge Vportion of the disc 36 is supported 'by means of a plurality' of -supporting links or arms 559, Yeach having itsupper end bolted to one of a plurality of vcircurnferentially spaced lugs 60 -carried by a collar 61 xedly secured to the intermediate section 49 Vof the shaft 26 and its lower end bolted to one of a Vplurality of lcircumferentially spaced 63 having its outer Yend portion xedly vsecured to the bottom and -one side of one of said vessels 31, as by welding, and its inner lend Aportion Ytixe'dly secured, as 4by bolting, to one of a plurality of circumferentially spaced dependent lugs 64, in the form of short sections of I-beams, welded to the'undersurface Vof the disc 30 (see Figs. 4 and 7). y

Means lmay be provided for holding the cylindrical vessels 31 -in their upright position encircling -the shaft 2'6. =In the particular lembodiment of the invention 'illustrated, such means are shown as comprising a disc 6'5 composed of two semi-annular flat pieces-66, 66, the `inner adjacentstraight edges'of which are provided'with flanges which are bolted together to form the complete'disc. This lis to permit of assembling the disc within the pressure mediate section 49-of the shaft 26, so-that tlie disc will rotate with the shaft. The vupperend portions of the vessels 31 are held in their upright position by 'the disc 65, as by means of a plurailty of Vbracing strips'or arms 68 Each arm 68 has its-outerendboltedftoalug 69j'welded on the outer surface of one of the vessels 31 andits inner end portion xedly secured, asby bolting, to the upper surface of the disc 65.

The upper and ylower distributive assemblages 32,v '33 are identical in construction and, as s'hown in Fig. 4, each comprises an annular trough-shaped stationary member 34 having a plurality of compartments or manifolds formed therein; a tube sheet disc valve 35 slidably mounted on the shaft 26 for rotation therewith; and a spring support disc 36 Vixedly mounted on the shaft 26 and supporting a plurality of coiled springs 37 which engage the tube sheet discsvalve 35 and Ytightly press it against the open end -of the annular stationary member'34.

The upper and lower annular vstationary members 34 are identical in construction and, as shown in yFigs. 4, 5, 8 and 9,-each is formed in the shape of an annular trough having an annular top`(or bottom) 'wall'70 and'annular side walls, 71, 72 (see Figs. 4 and9). p

The member 34 is -divided into a plurality vof cornpartments .or manifolds, vas bymeans -of al'pluralityo'f circumferentially Aspacedapairs of wall members 73ex- :tending vtransversely of `the member .34 .and having their top (or bottom) and side walls welded to the top (or P' bottom) and side walls ofthe member 34 to form gastight joints. Seven such compartments or manifolds are shown and, for the purpose of clarity of description, designated manifolds a, b, c, d, e, f and g, respectively. See Fig. 8.

The upper member 34 of the upper distributive assemblage 32 is held stationary relative to the rotation of the shaft 26 and the upper tube sheet disc valve 35 by the upper inlet-outlet conduits- 40, 41, 42, 43, 44, 45 and 46, which are welded to the upper cap closure member 23 and have their lower ends connected, as by welding, to the manifolds a, b, c, d, e, f and g, respectively, in the upper member 34 to provide communication therewith.

The lower member 34 of the lower distributive assemblage is held stationary relative to the rotation of the shaft 26 and the lower tube sheet disc valve 35 by the lower inlet-outlet conduits 40', 41', 42', 43' 44', 45', and 46', which are welded to the lower cap closure 24 and have their upper ends connected, as by welding, to the manifolds a, b, c, d, e, f and g, respectively, in the lower member 34 to provide communication therewith. f

The upper and lower tube sheet disc valves are identical in construction and, asshown in Fig. 4, each comprises a flat metal disc having a plurality of circumferentially spaced circular openings 74 formed in a circular row adjacent its periphery. The disc is provided with a collar 75 having a plurality of radially extending reinforcing ribs welded to its bottom surface or cast integral therewith. The collar 75 is keyed on the upper (lower) section of the shaft 26 to have longitudinal movement therealong as well as rotative movement therewith, as by means of a set screw 76 slidably engaging in a longitudinal groove 77 formed in the upper (lower) section of the shaft 26. A second collar 78 is fixedly secured to the shaft 26 immediately beneath the collar 75 to limit the inward movement of the disc as it moves longitudinally of the shaft 26. The disc 35, as well as the collar 75, are loosely fitted on the shaft 26 so that the disc valve can be moved slightly to conform to any change in the plane of the engaged surface of the stationary member 34, due to unequal expansion and contraction.

The tube sheet disc 35 is so mounted on the shaft 26 i fc, d, e, f and g, so that each manifold will be in communication with a group of the circular openings.

The upper and lower spring support discs 36 are identical in construction and, as shown in Fig. 4, each cornprises a metal disc mounted on the shaft and having a hub 79 provided with a plurality of circumferentially spaced radial ribs or webs welded to the under face of the disc to strengthen it. The hub is fixedly secured to the shaft as by a set screw. A plurality of vertically extending circumferentially spaced coiled springs 37 are interposed between the tube sheet disc valve 35 and the spring support disc 36. In order Vto insure that the springs 37 remain in proper position, they are mounted on and between short stubs 80 extending upwardly from the disc 36l and short corresponding stubs 80' extending downwardly from the disc 35. The construction and arrangement is such that the springs 37 will keep the disc valve 35 evenly and rmly pressed into engagement with the under surface of the annular stationary member 34.

The upper and lower flexible pipes 38, 39, which conneet the upper and lower end portions ofthe adsorbent material containing vessels 31 to the upper and lower distributive assemblages are identical in construction and, as shown in Figs. 4 and 10, each comprises a thin walled cylindrical metal tube having the greater portion of its wall formed in a sinuous shape to give it flexibility, the outer cylindrical end of each tube is detachably secured t0 a nozzle 81 formed on the upper (lower) end portion of the vessel 31, as by strapping. The cylindrical inner end of the tube is provided with an integral ange 82. The opening in the cylindrical inner end of the tube is aligned with one of the circular openings 74 formed in the upper (lower) tube sheet disc valve 35 and the tange 82 is detachably secured to the outer surface of the disc valve, as by countersunk bolts, so that the inner surface of the disc wall will be smooth and uninterrupted (see Fig. 4).

To prevent the escape of gas between the rotating tube sheet disc valve 35 and the manifolds in the member 34, sealing ring gaskets 83 are placed at the juncture of the side walls of the member 34 and the disc valve 35. The ring gaskets 83 are wedged into annular troughs 84 secured, as by welding, to the outer surface of the side walls of the member 34. Each trough comprises an annular top (bottom) wall 85 and an annular side wall 86. The ring gaskets 83, preferably and as shown, comprise a plurality of annular strips of packing, generally rectangular in cross section and made of any suitable material, such as teflon or impregnated asbestos.

The seven manifolds a, b, c, d, e, f and g are sealed off from each other by means of cross seals 87, each sealed into a recess 88 formed by the adjacent end walls of the manifolds and a bottom plate 89 vertically spaced from the open end of the manifolds (see Figs. 8 and 9). Each cross seal is tightly wedged in its recess with its outer ends in tight engagement with the adjacent side walls of the annular seals 83 and with its bottom surface in sealing engagement with the upper (lower) surface of the tube sheet disc. In order for the outer ends of the cross seals to engage the adjacent side walls of the annular seals 83, the portions of the side walls 71 and 72 of the member 34 which extend between each pair of adjacent transverse members 73 are cut away, as indicated at 90, for a distance equal to the thickness of the seals 83 (see Fig. 9).

rlhe widths of the manifolds a, b, c, d, e, f and g are Vsubstantially the same as the internal diameters of the circular openings 74 in the tube sheet disc 35, so that each cross seal can effectively seal o one of the openings.

Each of the openings 74 formed in the upper tube sheet disc 35 is in vertical alignment with a corresponding one of the openings 74 formed in the lower tube sheet disc 35 and each of the cross seals 87 which separate the manifolds a, b, c, d, e, f and g formed in the upper stationary member 34 is in vertical alignment with a corresponding one of the cross seals 87 which separate the manifolds a, b, c, d, e, f and g formed in the lower stationary member 34.

When the rotary disc valve 35 and the vessels 31 are stationary, the foregoing arrangement, in effect, divides the adsorbent material containing vessels 31 into seven groups, with one group connected to communicate with the manifolds a, one group connected to communicate with the manifolds b, one group connected to communicate with the manifolds c, one group connected to communicate with the manifolds d, one group connected to communicate with the manifolds e, one group connected to communicate with the manifolds f, and one group connected to communicate with the manifolds g. Each group of vessels 31, together with the upper and lower manifolds with lwhich they are in Icommunication form separate flow passages through the adsorber so that seven separate, distinct and continuous ows of iluid may pass through the apparatus. Each ow entering the upper distributive assemblage by means of one of the inlet-outlet conduits 40, 41, 42, 43, 44, 45 or 46, thence through one of the groups of vessels 31 into the lower distributive assemblage and out through one of the inlet-outlet couduits 4G', 41', 42', 43', 44', 45', or 46. As the vessels 31 and the upper and lower ldisc valves 35 rotate, each of the flows of uid will successively pass through the vessels 31. For convenience in description, each 'ow passage is called a stage, in which either adsorption, activation, or purging takes place, depending upon the :particular'uid flowing therethrough. Also, the'vessels 31 are called zones, in which either adsorption, activation,

therein, as by welding, to form a gastight joint between the outervperipheral edge ofthe disca'nd the side wall of the .member "91. The lowerarmular dis-c 94 forms a support `for an elongated'annular fluid treating material lcontainer .95. The container l95 is removably mounted .within themember 91, with its 'bottom endresting on the annular disc94 and with the longitudinal open end of the container aligned with the opening in the disc.

The tubular member 91 has a tapered side wall for .a purpose hereinafter to be described and is 44provided with upper and lower circular openings 96 in which are se- `cured, as by welding, the nozzles 81 to which the upper Vandlower flexible pipes 38 and 39 are secured.

A'baflie member 97 is mounted in'the space .between 'thebottom of. the member 91 yand the annular disc 94, and

an .upper baie member 98 Ais secured .to the underside ofithe cover plate 93 and is removable'therewith. The upperandlower .baille members 98 and 97 are identical in construction and, as shown in Fig. l0, each comprises a generally elliptical-shaped flat sheet 99 extending upwardly (downwardly) from the bottom (top) of the member 91 to insure an even Iiiow of fluid through the member 91; a side wall forming Amember `100;'and insulating material 101 placed within the pocket .formed by the members 99 and 100 and the bottom V(top) wall of the member 91 (see Fig. 10).

The `containers 95 are identical in construction and, as

shown in Figs. l and .11, each comprises two concentric 'tubular screens 102, 103, held in spaced-apart relation by a plurality of 'longitudinal radialfms 104, with `the annular space between the screens closed at .the bottom, as by a flanged annularplate 105. The `mesh 'of the screens is such as to retain a granular adsorbent material 106.in the annular. space between the screens. In the instant case, the adsorbent material may ybe of any adsorbent having characteristics substantially like silica gel or the gel of other activated hydrous oxides. Preferably, silica gel is used.

Each of thecontainers 95 is 4closed at its top by means of concentric hoops or metal bands 107, v108 mounted on the concentric screens v102, 103, and a cover plate 109 is detachably connected to the inner hoop or band 108, as by screws, and having a depending annular lilange 11,0 yfitting between the hoops or bands 107, 108. A depending cylindrical lin .111 is secured to the flange 110 and projects downwardly between and below the 'hoops or bands .107, 108, and lits in slits 112 formed in the upper ends of the radial fins `104, all as shown in Figs. l0 and 11. 'The construction is such that, as the silica gel-settles down, leaving .a space between the top -portion ofthe wire vscreens devoid of silicagel, the fin 111 will prevent Huid from passing-'through the space..

' Mounted withinfthe inner Wire screen 103 is an inverted substantially conically shaped baille member 113. The

baille member -113 -is closedfat its apex which extends band 108, as by welding. `Preferably, the baille member -113is made of .thin sheetmetal.

`When`the vcontainer A95 is mounted within 'the hollow between =theclosure disc 116 and the side wall of the vthrough inlet-outlet conduit 41.

member "91, as lshown in Fig. l`0,`the,elongate'd annular 'space .between the walls of the member 91 and ftheintverted conical bale member 13 forms an elongated frusto-conically shaped duct which is annularn cross section. The annular.container, filled with silica gel,`is `positioned in the duct between themembers 91 and `113 in such manner that it forms a' barrier...extending 'longitudinally across'thedu-ct from top to bottom. The cross sectional areas ofthe duct at its top andbottom are substantially equal and the'tapers of its side walls are such that a substantially .uniform velocityis obtained on both .sides of the barrier as `'fluidis transferred from the upstream tothe downstream side, regardless of the direction .of flow, thereby creating a substantially constant 4static hea-'d over the face of the barrier, resulting in a substantially uniform .distribution of the llluid throughout the entire barrier'area. Thus, itwilllbe seen thatbyusing the V'members .91 'and :113, .as bale members, the-entirearea is madeuse .of with resultant increase in eiciency, ca-

pacity an'd economy.

'Means may be provided so that the containers 9,5 which v.hold theadsorbent material may readily be removedfrom and replaced inthe vessels 31. As shown, such means may comprise an opening`114 formed in the top of the `vessel 20`havinga cylindrical member 115 welded therein and provided with a readily-removable closure disc 116 secured in .the upper end of the member .115, as by means .ofa `split shear ring'.117 .bolted'thereto andtted into a 'circumferential .recess "118 yformed in the ,inner surfaceof themember 115, and anjO-ring packing 1,19 mounted member 1'15 to insurel gas tightness.

The'ows of the various `gases through the various stages of'theadsorber and the auxiliary apparatus are schematically shown in Fig. 1.

As. there shown, the naturalfgasis supplied under high pressure. from about 800 p. s. i..to about'lOOO p. s. i. by

.r pipe line 4 and enters manifold a of the upper distributive assemblage through inlet-.outlet conduit 40. From the manifold a' the gaspasses through openings 74formed in the upper .tube sheet disc valve 35 and exible pipes 38 into the .upper end portion of the group of vessels 31 which areat that time in-.communication with the manifold a. The `gas passes down vthrough the silica gel beds therein into the bottoms of the vessels. The baffle members 113, in cooperation with the taperedside walls of the vessels 31, insure a substantially uniform .flow an'ddistributionofthe gas through the silica gelbeds,

vwhich adsorb some of the HES content from the gas.

From the .bottoms of the vessels 31, the now partially Adried ,gasV passes through outlet pipes 39 and openings 74 infthe lower tube sheet disc valve'35 into the manifold .a of the lower distributive assemblage.

From the lower manifold a of the lower distributive assemblage, thegaspasses through inlet-outlet conduit 40 and pipe line 5 to the second adsorption stage and enters manifold b of the lower distributive assemblage From the lower manifold b the `gaspasses through openings 74 in the tube sheet.disc valve 35 `and inlet -K pipes 39 into the lower end portion of the group of vessels 31 which are at that time incommunication withmanifoldb. The gas passes upwardlythrough the vessels 31 ofthe .second .group and through thesilica. gel beds therein into the tops ythereof, the remaining I-I'2S content of the gas being adsorbed Vduring itspassage through'the silica gel beds.

jFrom the tops of the vessels'3l .of the vsecond adsorption group, the gas passes through pipes .38 and openings "74 inthe upper tube sheet disc valve of the upper distributive qassemblage into the upper manifold b.

From the upper manifold 'bthe gas .passesthrough inlety outlet pipe '41. and-pipe line 6 .to the various points of stage. The activation gas, a captive gas, is heated in a heater 2, where its temperature is raised to from 250 F. to 400 F. From the heater, the heated activation gas passes through pipe line 7 and inlet-outlet conduit 45 into the lower manifold f of the lower distributive assemblage. From the manifold f the hot activation gas passes through openings 74 in the lower tube sheet disc valve 35 and flexible pipes 39 into the lower end por tions of the groups of vessels 31 which are at that time in communication with manifold f. The gas passes upwardly through vessels 31 of the rst activation group and through the silica gel beds therein into the tops thereof. As the hot gas passes through the adsorbent material it removes the adsorbed H2S therefrom. From the tops of the vessels 31, the hot H28 laden gas passes through fiexible pipes 38 and openings 74 in the upper tube sheet disc valve 35 into the upper manifold f. From the upper manifold f, the hot gas passes through inlet-outlet conduit 45 and pipe line 8 to the blower 3 and is recycled by the blower through pipe line 9 and heater 2 back through the first activation stage. This recirculation process is continuous.

In order to effect the complete removal of the H28 content of the gas being treated, a second activation cycle following the first activation cycle is provided. The activation gas, a captive gas, is heated in the heater 2', where its temperature is raised to about 500 F. From the heater, the heated activation gas passes through pipe line 11 and inlet-outlet conduit 43' into the lower manifold d of the lower distributive assemblage. From the manifold d the hot activation gas passes through openings 74 in the lower tube sheet disc valve 35 and flexible pipes 39 into the lower end portions of the group of vessels 31 which are at that time in communication with the manifold d. The gas passes upwardly through vessels 31 of the second activation group and through the silica gel beds therein into the tops thereof. As the hot gas passes through the adsorbent material it removes all remaining H2S therefrom. From the tops of the vessels 31, the hot H28 laden gas passes through flexible pipes 38 and openings 74 in the upper tube sheet disc valve 35 into the upper manifold d. From the upper manifold d, the hot gas passes through inlet-outlet conduit 43 and pipe line 12 to the blower 3', and is recycled by the blower through pipe line 13, heater 2', and pipe line 11, back through the second activation stage. This recycling process is continuous.

In order to prevent dilution of the recycling activation gases and to prevent any loss of HZS into the effluent stripped gas from the last adsorption stage, three purging stages are employed, a first purging stage immediately preceding the first activation stage, a second purging stage interposed between the first and second activation stages, and a third purging stage immediately following the third activation stage.

A portion of the recycling activation gas, used in the first activation stage, fiowing through pipe line 9, is continuously diverted for use as the purging medium in the first purging stage and passes through pipe line 14 and inlet-outlet conduit 46 into the lower manifold g of the lower distributive assemblage. the lower distributive assemblage the purging gas passes through openings 74 in-the lower tube sheet disc valve 35 and flexible pipes 39 into the lower portions of the group of vessels 31 which are at that time in communication with manifold g. The gas passes upwardly through the vessels 31 of the first purging stage and through the silica gel beds therein into the tops thereof. As the purging gas passes through the adsorbent material it removes the slippage natural gas, thereby purging the beds. From the tops of the vessels 31 the eiuent gas, consisting substantially of slippage gas from the first adsorption stage, passes through flexible pipes 38 and openings 74 in the upper tube sheet disc valve 35 into the upper manifold g. From the upper manifold g the gas passes From the manifold g of 1.2 through inlet-outlet conduit 46 and pipe line 15 into pipe line 4 and joins the natural gas being treated on its way to the adsorber.

A portion of the recycling activation gas used in the second activation stage flowing through the pipe line 13 is continuously diverted for use as the purging medium in the second purging stage and passes through pipe line 16 and inlet-outlet conduit 44 into the upper manifold e of the upper distributive assemblage. From the manifold e the purging gas passes through openings 74 in the upper tube sheet disc valve 35 and flexible pipes 38 into the upper end portions ofthe group of vessels 31 which are at that time in communication with manifold e. The gas passes downwardly through the vessels 31 of the second purging -stage and through the silica gel beds therein into the bottoms thereof. As the purging gas passes through the adsorbent material therein it removes the slippage activation gas from the first activation stage, thereby purging the beds. From the bottoms of the vessels 31, the effluent gas, consisting substantially of slippage activation gas, passes through exible pipes 39 and openings 74 in the lower tube sheet disc valve 35 into the lower manifold e. From the lower manifold e the gas passes through inlet-outlet conduit 44 and pipe line 17 to pipe line 10 and joins the recycling activation gas used in the first activation stage.

The gas used as the purging gas in the third purging stage is obtained by continuously diverting a portion of the flow of the stripped natural gas through pipe line 6 from the last adsorption stage of the adsorber, through pipe line 18 and inlet-outlet conduit 4Z into the upper manifold c of the upper distributive assemblage. From the manifold c the purging gas passes through openings 74 in the upper tube sheet disc valve 35 and flexible pipes 38 into the upper end portions of the group of vessels 31 which are at that time in communication with manifold c. The gas passes downwardly through the vessels 31 and through the silica gel beds therein into the bottoms thereof. As the purging gas passes through the adsorbent material it removes the slippage activation gas from the second activation stage, thereby purging the beds. From the bottoms of the vessels 31, the effluent gas, consisting substantially of slippage activation gas, passes through fiexible pipes 39 and openings 74 into the lower tube sheet disc valve 35 into the lower manifold c. From the lower manifold c the gas passes through inlet-outlet conduit 42 and pipe line 19 to pipe line 12 and joins the recycling activation gas used in the second activation stage.

The valved pipe line 17 connecting pipe line 13 to blower 3 permits bleeding a regulated quantity of the recycling activation gas used in the second activation stage into the recycling stream of activation gas in the first activation stage.

The employment of the two activation stages, the three purging stages, and the regulated bleeding of the captive stream of activation gas from the second activation stage into the first activation stage, as above outlined, effects a very complete removal of H28 from the gas being treated, and efficiently effects the build up of the desired concentration of HZS in the first captive activation stream, at which point a portion of the recycling activation gas is bled off through the pipe line 10 as the nished product or sent to a condenser for liquefaction.

The gas being treated makes two passes through the adsorber, while each of the activation gases and each of the purging gases each make a single pass through the adsorber. For convenience in description, the stage of the adsorber through which the first adsorption passage of the gas being treated is made, is called the first adsorption stage, the stage through which the second adsorption passage is made is called the second adsorption stage, the stage through which the first activation gas passes is called the first activation stage, the stage through clockwise, 'as vie'wedin Fig.'2, and at'arate such that the efiiuent gasow'from the purging stagesvvill be substantially volumetric With'the ,slippage gas Vbrought into these'stages as the vessels 31 are 'rotated;'thus, it will'be seenthat, as the valves `35 `and fthe vessels 31 rotate, veach of the vessels 31 will`A be successively 'brought into .communication with'the `manifolds ggf, e, d, c,'b and a in the upper and Vlower r'distributive assemblages, so that each'vessel `31 will, in turn, "become a first purging zone, a first activation zone, a second purging zone, a second 4activation zone, `a third Apurging zone, a second adsorption zone, and afirst adsorption Zone.y

Suitable stop valveszare provided at any desired point in any Vpipe line to ,provide means forcontrolling-the ow of the various mediums through thevarious stages of the adsorber and the auxiliary-apparatus.`

From the foregoing, it readily Vwill -b'eseen that there has been provided a 'novel and improved cyclic adsorptionprocess for treating fluids to vremove and/or recover yparticular constituents therefrom, in vwhich Ya plurality of activation'steps and 'a plurality of purging steps are employed to insure a moreeflicient process and the nearly complete removal of the particular constituent to be recoveredfromthe fluid being treated; Va process particularly adapted for removing kand/or Vrecovering H2S from natural gas.

While some of the flows of fluidf through the apparatus have been described as entering the top distributive assemblage and flovvingdownward to and out of the'bottom distributive assemblage, obviously, the'flows may bein either direction.

Obviously, tooythepresent invention vis not restricted to the Vparticular embodimentthereof hereinshown and described.

What is claimed is:

1. In Vtheprocess of itreatingifluid to remove and/or recover aparticular constituent contained therein'involving the 'contact of adsorbent material vvvi'th the yHuid, to be treated With resultant adsorption of "the particular constituent by .the adsorbent material andthe-*subsequent treatment of the adsorbent materialwith a heated medium to vaporize and remove the partcular'cons'tituent and thereby reactivate the adsorbent material for further contact with the uid to 'be treated, the improvement which comprises rotatinga series of separated beds of adsorbentmaterial directly and in, succession.and substantially continuously relative to and through a `first purging stage, a rst activation stage, a second purging stage, a second activation stage, a third purging stage, and at least one adsorption stage; continuously directing a fiow of the uid being treated, under high pressure and in succession, through the adsorption stage so that the particular constituent content thereof which is to be removed will be adsorbed by the adsorbent material therein; continuously heating and recycling a fiow of activation medium through said rst activation stage to desorb the particular constituent contained in the beds of adsorbent material therein and reactivate the adsorbent material; continuously heating and recycling a iiow of activation medium through said second activation stage to desorb the particular constituent contained in the beds of adsorbent material therein and reactivate the adsorbent material; continuously diverting a portion -trate'd, the valve discs 35 andjthevessels 31 'arerotated `14 of the flow of therecycling 'activation medium used in the 4 first activation stage `and directing `its flow lrthrough the rst'purging stage to remove all ofthe fluid being treated therefrom; continuously directing thefiow of the effluent fiuid from the first purging stage into the tiow `of the fluid being treated onits Way to the first adsorption stage; continuously'diverting a portion of the flow ofthe `recycling activationr medium used in the 'Second activation stage and directing its flow through the second purging stage to'remove all of the activation medium therefrom; continuously directing the owof the'lefuent fluid from the second purging 4stage into the ow of'the recycling activation medium used in the first activation stage; continuously 'diverting a portion of the flow of the effiuent strippedfluid being treated from'the last of the adsorption stages and directing its flow through the third purging stage to remove all of the activation 'medium therefrom; continuously directing the flow of the effluent fluid fromthethird purging stage into the flow'of the'recyclinjg activation medium used in the second activation stage; continuously bleeding off av "determined rquantity of the flow ofthe recycling activation medium used in the second'activation stageinto the fiow ofthe recycling activation medium used in the first activation stage; and continuously withdrawing a Aportion of the activation medium used in the first activation stage from its recycling path-after ithas become highly` concentrated in desorbedrparticular constituent, as the finished product.

2. In the processv'of treating flui'cl to remove and/or recovera particular constituent therefrom involving the contact ofadsorbent materialwith'the uid to be treated Withresultant adsorption of the particular constituent by the adsorbent material and the subsequent treatment of vthe adsorbent materialwith Va heated medium to vaporize and remove the particular constituent and thereby reactivate the adsorbent materialfor further contact with the fluid to be treated, the improvement which comprises maintaining at least one bed of adsorbent material in each of a Vplurality of zones; continuously heating and recycling a first flow of a captive 'activation medium through at least one of said Zones'to desorb the particular constituent contained in the beds of adsorbent material'therein and reactivate the adsorbent material; continuously heating and Yrecycling a second flow of a captive activation medium .throughatleast another one of said zones to desorb the particular constituent contained in the beds of adsorbent material therein and reactivate the adsorbent material, continuously directing a first fiow of a .purging medium through at leastanother one of said zones to purge the zone; continuously directing a second flow of a purging medium through at least another one of. said zones to purge the zone; continuously directing a third flow of apurging `medium through at least another one of said zones to purge-the zone; continuously directing-the flow Aof the uid being treated through the remainder'of said :zones so that some ofthe particular constituent of the fluid will be ladsorbed `by the Vadsorbent materialitherein;*periodically shifting the relative lpositions 'ofthe 'particular adsorbent material and the particular liow of fluid in each of said zones so that each zone becomes in succession a first purging zone, a first activation zone, a second purging zone, a second activation zone, a third purging zone, and an adsorption zone; continuously diverting a portion of said rst flow of a captive recycling activation medium for use as the first purging medium and continuously directing the fiow of the effluent fluid from the first purging zone back into the flow of the fluid being treated on its Way to the irst adsorption Zone; continuously diverting a portion of said second flow of a captive recycling activation medium for use as the second purging medium and continuously directing the fiow of the efuent fluid from the second purging zone into said first ow of a captive recycling activation medium; continuously diverting a portion of the ow of the stripped effluent fluid being treated from the last of the adsorption zones for use as the third purging medium and continuously directing the ow of' the efliuent fluid from the third purging zone into said second flow of a captive recycling activation medium; continuously bleeding off a determined quantity of the flow of the recycling activation medium used in the second activation zone into the ow of the recycling activation medium used in the first activation zone; and continuously withdrawing a portion of the activation medium used in the first activation zone from its recycling path, after it has become highly concentrated in desorbed particular constituent, as the finished product.

3. A process for removing and recovering H2S from natural gas from which substantially all water vapor and condensable hydrocarbons have previously been removed therefrom comprising rotating a series of separated beds of adsorbent material directly in succession and substantially continuously relative to and through a first purging stage, a rst activation stage, a second purging stage, a second activation stage, a third purging stage, and a plurality of adsorption stages; continuously directing a flow of the gas to be treated under high pressure and in succession through the adsorption stages so that the H28 content thereof will be adsorbed by the adsorbent material therein; continuously heating and recycling a ow of activation medium through said first activation stage to desorb the H2S contained in the beds of adsorbent material therein and reactivate the adsorbent material; continuously heating and recycling a iow of activation medium through said second activation stage to desorb the H contained in the beds of adsorbent material therein and reactivate the adsorbent material, continuously diverting a portion of the ow of the recycling activation medium used in the first activation stage and directing its flow through the first purging stage to remove all of the gas being treated therefrom; continuously directing the flow of the eiuent gas from the first purging stage into the flow of the gas being treated on its way to the first adsorption stage; continuously diverting a portion of the ow of the recycling activation medium used in the second activation stage and directing its ow through the second purging stage to remove all of the activation medium therefrom; continuously directing the ow of the effluent gas from the second purging stage into the flow of the recycling activation medium used in the first activation stage; continuously diverting a portion of the flow of the effluent stripped gas being treated from the last of the adsorption stages and directing its flow through the third purging stage to remove all of the activation medium therefrom; continuously directing the flow of the eiuent gas from the third purging stage into the ow of the recycling activation medium used in the second activation stage; continuously bleeding off a determined quantity of the flow of the recycling activation medium used in the second activation stage into the flow of the recycling activation medium used in the first activation stage; and continuously withdrawing a portion of the activation medium used in the first activation stage from 16 its recycling path after it has become highly concentrated in H2S, as the finished product.

4. A process for removing and recovering H2S from natural gas from which substantially all water vapor and condensable hydrocarbons have previously been removed therefrom comprising maintaining at least one bed of adsorbent material in each of a plurality of zones; continuously heating and recycling a rst flow of a captive activation medium through at least one of said zones to desorb the H2S contained in the beds of adsorbent material therein and reactivate the adsorbent material; continuously heating and recycling a second flow of `a captive activation medium through at least another one of said zones to desorb the H2S contained in the beds of adsorbent material therein and reactivate the adsorbent material; continuously directing Ia first flow of a purging medium through at least another one of said zones to purge the zone; continuously directing a second flow of a purging medium through at least another one of said zones to purge the zone; continuously directing a third flow of a purging medium through at least another one of said zones to purge the zone; continuously directing the flow of the gas being treated through the remainder of said zones so that some of the H2S content of the gas will be adsorbed by the adsorbent material therein; periodically shifting the relative positions of the particular adsorbent material and the particular flow of gas in each of said zones so that cach zone becomes in succession a first purging zone, a rst activation zone, a second purging Zone, a second activation zone, a third purging zone, and an adsorption zone; continuously diverting a portion of said first ow of a captive recycling activation medium for use as the first purging medium and continuously directing the ow of the effluent gas from the first purging zone back into the flow of the gas being treated on its way to the first adsorption zone; continuously diverting a portion of said second flow of a captive recycling activation medium for use as the second purging medium and continuously directing the flow of the effluent gas from the second purging zone into said first flow of a captive recycling activation medium; continuously diverting a portion of the flow of the stripped effluent gas being treated from the last of the adsorption zones for use as the third purging medium and continuously directing the flow of the effluent gas from the third purging zone into the second ow of a captive recycling activation medium; continuously bleeding off a determined quantity of the fiow of the recycling activation medium used in the second activation zone into the flow of the recycling activation medium used in the first activation zone; and continuously withdrawing a portion of the activation medium used in the first `activation zone from its recycling path, after it has become highly concentrated in desorbed H2S, as the finished product.

References Cited in the file of this patent UNITED STATES PATENTS 2,799,361 Miller July 16, 1957 

1. IN THE PROCESS OF TREATING FLUID TO REMOVE AND/OR RECOVER A PARTICULAR CONSTITUENT CONTAINED THEREIN INVOLVING THE CONTACT OF ADSORBENT MATERIAL WITH THE FLUID TO BE TREATED WITH RESULTANT ADSORPTION OF THE PARTICULAR CONSTITUENT BY THE ADSORBENT MATERIAL AND THE SUBSEQUENT TREATMENT OF THE ADSORBENT MATERIAL WITH A HEATED MEDIUM TO VAPORIZE AND REMOVE THE PARTICULAR CONSTITUENT AND THEREBY REACTIVATE THE ADSORBENT MATERIAL FOR FURTHER CONTACT WITH THE FLUID TO BE TREATED, THE IMPROVEMENT WHICH COMPRISES ROTATING A SERIES OF SEPARATED BEDS OF ADSORBENT MATERIAL DIRECTLY AND SUCCESSION AND SUBSTANTIALLY CONTINUOUSLY RELATIVE TO AND THROUGH A FIRST PURGING STAGE, A FIRST ACTIVATION STAGE, A SECOND PURGING STAGE, A SECOND ACTIVATION STAGE, A THIRD PURGING STAGE, AND AT LEAST ONE ADSORPTION STAGE; CONTINUOUSLY DIRECTING A FLOW OF THE FLUID BEING TREATED, UNDER HIGH PRESSURE AND IN SUCCESSION, THROUGH THE ADSORPTION STAGE SO THAT THE PARTICULAR CONSITUTENT CONTENT THEREOF WHICH IS TO BE REMOVED WILL BE ADSORBED BY THE ADSORBENT MATERIAL THEREIN; CONTINUOUSLY HEATING AND RECYCLING A FLOW OF AC-TIVATION MEDIUM THROUGH SAID FIRST ACTIVATION STAGE TO DESORB THE PARTICULAR CONSTITUENT CONTAINED IN THE BEDS OF ADSORBENT MATERIAL THEREIN AND REACTIVATE THE ADSORBENT MATERIAL; CONTINUOUSLY HEATING AND RECYCLING A FLOW OF ACTIVATION MEDIUM THROUGH SAID SECOND ACTIVATION STAGE TO DESORB THE PARTICULAR CONSTITUENT CONTAINED IN THE BEDS OF ADSORBENT MATERIAL THEREIN AND REACTIVATE THE ADSORBENT MATERIAL; CONTINUOUSLY DIVERTING A PORTION OF THE FLOW OF THE RECYCLING ACTIVATION MEDIUM USED IN THE FIRST ACTIVATION STAGE AND DIRECTING ITS FLOW THROUGH THE FIRST PURGING STAGE TO REMOVE ALL OF THE FLUID BEING TREATED THEREFROM; CONTINUOUSLY DIRECTING THE FLOW OF THE EFFLUENT FLUID BEING TREATED ON ITS WAY TO THE FIRST ADSORPOF THE FLUID BEING TREATED ON ITS WAY TO THE FIRST ADSORPTION STAGE; CONTINUOUSLY DIVERTING A PORTION OF THE FLOW OF THE RECYCLING ACTIVATION MEDIUM USED IN THE SECOND ACTIVATION STAGE AND DIRECTING ITS FLOW THROUGH THE SECOND PURGING STAGE TO REMOVE ALL OF THE ACTIVATION MEDIUM THEREFROM; CONTINUOUSLY DIRECTING THE FLOW OF THE EFFLUENT FLUID FROM THE SECOND PURGING STAGE INTO THE FLOW OF THE RECYCLING ACTIVATION MEDIUM USED IN THE FIRST ACTIVATION STAGE; CONTINUOUSLY DIVERTING A PORTION OF THE FLOW OF THE EFFLUENT STRIPPED FLUID BEING TREATED FROM THE LAST OF THE ADSORPTION STAGES AND DIRECTING ITS FLOW THROUGH THE THIRD PURGING STAGE TO REMOVE ALL OF THE ACTIVATION MEDIUM THEREFROM; CONTINUOUSLY DIRECTING THE FLOW OF THE EFFLUENT FLUID FROM THE THIRD PURGING STAGE INTO THE FLOW OF THE RECYCLING ACTIVATION MEDIUM USED IN THE SECOND ACTIVATION STAGE; CONTINUOUSLY BLEEDING OFF A DETERMINED QUANTITY OF THE FLOW OF THE RECYCLING ACTIVATION MEDIUM USED IN THE SECOND ACTIVATION STAGE INTO THE FLOW OF THE RECYCLING ACTIVATION MEDIUM USED IN THE FIRST ACTIVATION STAGE; AND CONTINUOUSLY WITHDRAWING A PORTION OF THE ACTIVATION MEDIUM USED IN THE FIRST ACTIVATION STAGE FROM ITS RECYCLING PATH AFTER IT HAS BECOM HIGHLY CONCENTRATED IN DESORBED PARTICULAR CONSTITUENT, AS THE FINISHED PRODUCT. 